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A Familiar Riddle:

Posted on 2005-04-21
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Last Modified: 2009-09-10
Here's a familiar riddle...

WARDEN ENTERS ROOM.
WARDEN: You have been convicted and found guilty of a heinous crime. However!... you have been at best behavior and done good for society. THEREFORE!
WARDEN POUNDS FIST ON TABLE.
WARDEN: You have been given a chance of freedom! BUT there are a few conditions. FIRSTLY, this chance will be solved by either chance or intellect. There are two guards before you, each guarding a path. One path will lead to the prison. If you take the path to prison, and you WILL be imprisoned for life. The other path leads to the city. If you take the path to the city, you will be free. SECONDLY, you may only ask one guard one question. After you have asked your first question from a guard, they will remain silent and you must choose which path to take. THIRDLY, one guard has been instructed to speak only the truth! The other guard will tell you only lies! They will follow these orders. You will not be told which guard speaks the truth or which one lies. FOURTHLY, you may not ask one guard what another guard would say. Should you ask such a question, the guards will remain silent as if you asked no question.
WARDEN LEAVES ROOM.
SCENE ZOOMS PAST TABLE.
THERE ARE TWO GUARDS IN FRONT, EACH GUARDING A PATH.
What will you ask?
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Question by:Caudax
27 Comments
 
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by:sirspic
ID: 13840302
Ask either guard...

"What door will the other guard say leads to freedom?"
-because it has to go between both the lying and the truth telling guard both times...you will always get the wrong door.

Therefore, go with the opposite door and you are home free.
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by:ozo
ID: 13840316
"If I ask you if which path leads to the city, which would you indicate?"
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ozo earned 240 total points
ID: 13840323
"Has the guard in front of the path to the city been instructed to lie?"
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by:sirspic
ID: 13840330
o crap i didnt read the 4th one lol
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ID: 13841369
I like ozo's first answer best.
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by:ozo
ID: 13841453
The reply to my first answer could concievably be "I would remain silent."
My second answer could work better, but the warden only says that "The other guard will tell you only lies!", not that The other guard has been instructed to tell you only lies, so perhaps
"Has the guard who is guarding the path to the city been instructed to speak only the truth?"
would be safer.
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by:sublimation
ID: 13842249
Kill one and ignore the other...
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by:Wojciech Duda
ID: 13843579
This has to be like the first riddle EVER! Bleh...
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by:Diego Pazos
ID: 13845060
One has been ordered to tell the truth, and the other has been ordered to lie, so asking:

"Had you been ordered differently, what would you tell me is the path to the city?"

works just fine and doesn't involve asking them what the other would say.

As in the classic riddle, you should take the path they did NOT point you to.
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by:Navicerts
ID: 13846459
SECONDLY, you may only ask one guard one question


wouldnt this rule mean that any combination of "asking one guard if the other has (insert variation here)" not work.

seems to e like you can only ask one question total, and it must be directed twoard one guard.

-Navicerts
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by:Navicerts
ID: 13846472
never mind i get it :)
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by:Caudax
ID: 13847078
Ozo, props on the answers.

The first one I meant obviously to be excluded as well, even though it technically qualifies, so no points on that one.

The second one you will get points on.

Person who speaks truth and guards says no=go through
Person who speaks truth and does not guard says yes=go to other
Person who speaks lies and guards says no=go through
Person who speaks lies and guards says yes=go through

BUT!

There's still another question that can be asked so no points will be awarded until someone gives that answer or the deadline (April 27th) has been met.
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by:Caudax
ID: 13847082
EDIT: Person who speaks lies and guards says yes=go to other
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by:andyalder
ID: 13848872
>After you have asked your first question from a guard, they will remain silent and you must choose which path to take.

Since you aren't going to get an answer whatever you ask you might as well ask either of them what their wife has cooked for dinner. This will make both feel hungry and after a while they will go home to eat and you follow them out of the door to the city.
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by:Caudax
ID: 13852818
Having asked the question includes receiving the answer...
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by:Wwysdom
ID: 13855961
Actually, ozo's second answer can have 4 permutations.

>>"Has the guard in front of the path to the city been instructed to lie?"
Guard (Lies) (at path to city) : "No"
Guard (Truth) (at path to city) : "No"
Guard (Lies) (at path to jail) : "Yes"
Guard (Truth) (at path to jail) : "Yes"

If the answer is 'No', go through this door, else choose the other door

2nd
"Has the guard in front of the path to the city been instructed to tell the truth?"
Guard (Lies) (at path to city) : "Yes"
Guard (Truth) (at path to city) : "Yes"
Guard (Lies) (at path to jail) : "No"
Guard (Truth) (at path to jail) : "No"

If the answer is 'Yes', go through this door, else choose the other door

3rd
"Has the guard in front of the path to the Jail been instructed to lie?"
Guard (Lies) (at path to city) : "Yes"
Guard (Truth) (at path to city) : "Yes"
Guard (Lies) (at path to jail) : "No"
Guard (Truth) (at path to jail) : "No"

If the answer is 'Yes', go through this door, else choose the other door

4th
"Has the guard in front of the path to the Jail been instructed to tell the truth?"
Guard (Lies) (at path to city) : "No"
Guard (Truth) (at path to city) : "No"
Guard (Lies) (at path to jail) : "Yes"
Guard (Truth) (at path to jail) : "Yes"

If the answer is 'No', go through this door, else choose the other door
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by:arch_great
ID: 13857873
He can ask
"What answer you will give usually ,if anyone asks which road will go to the city "

The truth speaking guy will indicate the correct path

The liar cannot tell what he usually says since that is the truth and so has to give a different answer which will be the correct path indeed

Is this suggestion same as Ozo's first suggestion ?

Archana


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by:ViRoy
ID: 13861986

you ask both "did you sleep with the other guards wife?"
then when they are killing each other you walk 9/10ths the way down each path and determine which one is correct.
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by:ViRoy
ID: 13862023

"may i see whats at the end of the path before choosing"
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by:maharlika
ID: 13862668
"After you have asked your first question from a guard, they will remain silent and you must choose which path to take":  so what good will it do to ask ANY question, if they're not allowed to answer any?
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by:Caudax
ID: 13864501
Wwysdom, I was not asking for different permutations; although the question works similarly, it is not a permutation of ozo's question.

arch_great, it is the same as Ozo's first suggestion.

ViRoy, although your methods are certainly unorthodox and may work, the other unmentioned yet perfectly obvious rule is that once you go down a path you can't go back. Besides, if you do manage to arouse the guards to sufficient rage to murder one another and managed to find the path to the city, you would be arrested immediately at the city.

If you would take that logic then the answer would be: "The question doesn't matter. I pick the untrodden path that is not guarded by a guard which I know leads directly to the city." Another solution would then also be: "I hypnotize the guard with the manner of my question which asks if he guards the path to the city so that the guard will speak the truth whether or not the guard was supposed to lie."

The second question does nothing; the guard that lies says yes and the guard that speaks the truth says no. Now you know who lies, but that still doesn't get you any closer to discovering the path to the city.

Maharlika, I already addressed such a comment.
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by:SWOne
ID: 13877004
I walk up to one guard, and ask "are your shoes untied?" As he looks down, I knowck him out and, in one deft movement, grab his sword/gun/shockstick and hold it to the other guard's throat, at which point I say "Choose a door for me to walk through. This is not a question, so feel free to answer. And you'll be going first."
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by:tonsofpcs
ID: 13882701
You must remain silent after the question.
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by:Caudax
ID: 13883169
Does the guard who speaks the truth guard the door to the city?
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by:Wwysdom
ID: 13890722
That is so lame.
Logically, it's just a rephrase of ozo's answer, read 'PERMUTATION'.
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by:tonsofpcs
ID: 13931143
No, it is the inverse, not a permutation.  
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by:Wwysdom
ID: 13931664
It's a "permutation", alright.

From my comment:
>> "Has the guard in front of the path to the city been instructed to tell the truth?"
Guard (Lies) (at path to city) : "Yes"
Guard (Truth) (at path to city) : "Yes"
Guard (Lies) (at path to jail) : "No"
Guard (Truth) (at path to jail) : "No"

>> ... I was not asking for different permutations; although the question works similarly, it is not a permutation of ozo's question.

But let's just forget abt it and move on...
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